A J-15 carrier-borne fighter jet takes off from the flight deck of the aircraft carrier Liaoning during a maritime training exercise on July 1, 2017. The Chinese aircraft carrier Liaoning and its carrier strike group carried out realistic training in an undisclosed sea area on July 1, 2017. (eng.chinamil.com.cn/Photo by Li Tang)

The aircraft carrier Liaoning of the Chinese People's Liberation Army (PLA) Navy has reportedly launched an exercise in the West Pacific, with the island of Taiwan and Japan sensationalizing the voyage which experts said is normal and legitimate.

PLA Navy vessels led by Liaoning sailed through the waters northeast of the island of Taiwan and continued toward the southeast of Yonaguni Island, Japan, the defense authority on the island of Taiwan said in a press release on Wednesday.

Japan's Ministry of Defense Joint Staff said in a press release on Wednesday that it spotted the aircraft carrier Liaoning, together with two Type 052D destroyers, sailing in waters near Diaoyu Dao on Tuesday, before sailing through waters between Yonaguni and Iriomote islands, entering the Pacific Ocean on Wednesday.

It is the first time a PLA Navy aircraft carrier has sailed in the region, according to the Japanese press release. 

Reuters quoted Japan's defense ministry as saying that the Chinese carrier entered Japan's contiguous waters for the first time.

When asked about Liaoning's voyage into Okinawa's contiguous zone on Wednesday, Lin Jian, a spokesperson of the Chinese Ministry of Foreign Affairs, referred media to the relevant Chinese authority for more information , but stressed that the Chinese activities conformed to China's domestic law and the international law.

Fu Qianshao, a Chinese military expert, told the Global Times on Wednesday that the waters between Yonaguni and Iriomote islands, despite being narrow, remain a strait used for international navigation, and it is legitimate for the PLA Navy ships to sail through the strait.

The transit also showed that, in addition to the Miyako Strait, the PLA Navy has multiple passages in breaking the first island chain into the West Pacific, Fu said.